An internal combustion engine with such a clutch actuator mounted to an engine case is disclosed in Japanese Patent Laid-open No. 2008-138541.
In the internal combustion engine disclosed in Japanese Patent Laid-open No. 2008-138541, which is equipped with a twin clutch type transmission, a twin clutch operated by oil pressure is provided at an end portion of a main shaft of the transmission, and a clutch cover mounted to a right side surface of a crankcase is projected to the right side to cover the twin clutch.
In addition, along a mating surface of the crankcase for mating with the clutch cover, the crankcase is provided at its inner surface with a clutch actuator containing part bulged to the inner side. Further, a clutch actuator for engaging and disengaging the twin clutch is inserted into the clutch actuator containing part through an opening formed in that surface of the clutch actuator containing part which is the same as the mating surface, and the clutch actuator is detachably mounted.
In the manner of extending from the clutch actuator containing part of the crankcase, a control oil passage for supplying a working oil to the shift clutch is formed in communication with the inside of a side wall of the crankcase and the inside of a side wall of the clutch cover.